La comunicación desde una perspectiva sociocultural: secuencias de una conversación académica

En el marco del XV Encuentro del Consejo Nacional para la Enseñanza y la Investigación de las Ciencias de la Comunicación (CONEICC), celebrado en la Universidad Iberoamericana de la Ciudad de México en octubre de 2010, se realizó la presentación del libro de Raúl Fuentes “La comunicación desde una perspectiva sociocultural, acercamientos y provocaciones 1997-2007” publicado por el ITESO casi dos años antes. La presentación dio pie a una estimulante conversación en público entre el autor, el doctor Manuel Alejandro Guerrero, coordinador del Departamento de Comunicación de la Universidad Iberoamericana, y la maestra Gabriela Flores, académica de la misma institución. Gracias a la recuperación del registro digital, la conversación pudo ser reconstruida por escrito.ITESO, A.C

Minimization of measuring points for the electric field exposure map generation in indoor environments by means of Kriging interpolation and selective sampling

In a world with increasing systems accessing to radio spectrum, the concern for exposure to electromagnetic fields is growing and therefore it is necessary to check limits in those areas where electromagnetic sources are working. Therefore, radio and exposure maps are continuously being generated, mainly in outdoor areas, by using many interpolation techniques. In this work, Surfer software and Kriging interpolation have been used for the first time to generate an indoor exposure map. A regular measuring mesh has been generated. Elimination of Less Significant Points (ELSP) and Geometrical Elimination of Neighbors (GEN) strategies to reduce the measuring points have been presented and evaluated. Both strategies have been compared to the map generated with all the measurements by calculating the root mean square and mean absolute errors. Results indicate that ELSP method can reduce up to 70% of the mesh measuring points while producing similar exposure maps to the one generated with all the measuring points. GEN, however, produces distorted maps and much higher error indicators even for 50% of eliminated measuring points. As a conclusion, a procedure for reducing the measuring points to generate radio and exposure maps is proposed based on the ELSP method and the Kriging interpolation.This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors

Identificación de plantas hospedantes del virus moteado del haba (Vicia faba L.) en el departamento de Nariño.

Presenta los resultados obtenidos al inocular el virus moteado del haba en algunas especies de plantas cultivadas, malezas y algunas indicadoras del virus. El trabajo se llevó a cabo en el Centro de Investigaciones Obonuco (Nariño) en condiciones de invernadero (25 grados centígrados y 80 por ciento de humedad relativa) y en la Universidad de Nariño (14 grados centígrados de temperatura y 60 por ciento de humedad relativa). Se inocularon mecánicamente 21 especies pertenecientes a 6 familias en estado de plántulas, hojas desarrolladas y hojas desprendidas, con diluciones en agua destilada 1:0, 1:10, 1:100 y 1:1000 de savia obtenida de plantas de haba severamente afectadas por el virus del campo. Se pudo establecer que las especies que presentaron síntomas sistémicos mostraron mejor reacción cuando se inocularon en estado de plántula, mientras que síntomas de lesiones locales se manifestaron mejor en hojas desarrolladas. Chenopodium amaranticolor tuvo mejor reacción al virus bajo condiciones de campo, presentando síntomas sistémicos y lesiones locales. Nicotiana rustica presentó lesiones locales y síntomas sistémicos bajo condiciones de invernadero, N. tabacum var. White Burley produjo lesiones locales y Phaseolus vulgaris presentó un mosaico típico diferente al mosaico común y rugoso del fríjol. En las especies que reaccionaron positivamente a la inoculación hubo relación directa entre la concentración del virus inoculado y el número de plantas con síntomas sistémicos y/o número de lesiones localesHaba-Vicia fab

Análisis de regularidad en fibrilación ventricular: aplicación a registros de mapeado cardíaco

Las técnicas utilizadas en el análisis de la señal de fibrilación ventricular (FV), obtenida mediante sistemas de mapeado utilizando matrices de electrodos, extraen información del proceso a partir de parámetros calculados principalmente en el dominio del tiempo o de la frecuencia. El presente trabajo plantea la aplicación del índice de regularidad (IR), propuesto inicialmente para caracterizar la fibrilación auricular humana, a la señal de FV en un modelo experimental de corazón animal. Los resultados obtenidos muestran que el IR permite extraer información de los mapas de FV no disponible de forma directa cuando se estudian mediante los métodos clásicos en el tiempo o la frecuencia, cuantificando el grado de modificación en la morfología de las ondas de activación durante la FV

Analysis of spatial and temporal evolution of regularity maps during ventricular fibrillation

The analysis of cardiac mapping allows investigating the structure of ventricular fibrillation (VF). This work analyzes regions of interest (ROI) on cardiac maps obtained from the regularity analysis of VF records, providing information about signal regularity at each time instant and its spatial distribution. Cardiac registers were obtained using a 240- electrodes matrix located on left ventricle of isolated rabbit heart. A Langendorff system was used to maintain the heart perfusion. VF was induced by increased frequencies. Two groups of records were considered: control (G1: without physical training, N=10), and trained (G2, N=9). Records were processed in consecutive 4-second segments. Regularity index (RI) was obtained for every segment and channel. RI is a measure of similarity degree among local activation waves for every channel. A map with the RI value of each channel was computed for the 82 register segments. To analyze the spatial distribution of RI, a threshold value was determined experimentally and applied to the map in order to obtain the ROI. Two parameters were calculated: ROI spatial number (ROIsn, a measure of spatial fragmentation), and ROI spatial area (ROIsa, the percentage of area map occupied by ROI). In case of the time course of ROI, two additional parameters were computed: the number of electrodes which value had changed respect to the threshold in two consecutive maps (ROIen, which is related with the change size), and the cumulative absolute differences of RI values for the electrodes which are changed (ROIed). Obtained results for spatial analysis show that the number of ROI is lower for trained rabbits (ROIsn; G1: 4.465±1.120; G2: 2.,227±0.623; p<0.001), but ROI spatial area is greater than the control group (ROIsa; G1: 76.235±5.355%; G2: 88.163±2.885%; p<0.001). Time-course analysis shows that more electrodes change between consecutive maps in the control group (ROIen, G1: 22.455±6.702; G2: 13.877±2.485; p<0.001). No significant differences were found for ROIed (G1: 18.509±6.932; G2: 18.619±4.196; n.s.). To conclude, ROI analysis on RI maps applied to trained and no trained rabbits groups shows that VF cardiac response is more irregular and spatially fragmented in no trained group. In addition, regularity maps are more stable with time in trained group

Modifications on regularity and spectrum of ventricular fibrillation signal induced by physical training

The objective of this work is to study the modifications on cardiac response during ventricular fibrillation (VF) induced by physical training. The analysis was performed in the frequency domain of VF, and the regularity of the signal was also considered. Two sets of records were acquired: control (G1: without physical training, N=10), and trained (G2, N=9). Cardiac registers were obtained using a 240-electrodes matrix located on left ventricle of isolated rabbit heart. A Langendorff system was used to maintain the heart perfusion. VF was induced by increased frequencies. To analyze the time course of VF, records were processed in 4-second segments. For every segment and channel, Welch periodogram with Hanning window, two non-overlapped sections and zero padding, was computed. Parameters considered in frequency domain are: dominant frequency (DF) and normalized energy (NE: spectral energy in the window DF±1Hz, normalized by spectral energy in 5-35Hz band). For every segment and channel, a regularity analysis of VF was performed, obtaining the regularity index (RI), which is a measure of similarity among local activation waves present in every channel. Mean values for the parameters (DF, NE and RI) of the whole set of electrodes were computed for every segment. Obtained results show that DF is lower for trained rabbits (G1: 18.234±1, 241Hz; G2: 14.370±0, 866Hz; p<0.001). NE is greater for this group (G1: 0.140±0.006; G2: 0.263±0.017; p<0.001), suggesting a greater spectral concentration around DF. Finally, a greater regularity has been observed in the fibrillation signal for trained group (IR, G1: 0.756±0.026; G2: 0.834±0.014; p<0.001). As a summary, the results suggest that both spectral characteristics and regularity of VF signal are clearly different for G1 and G2 groups. The trained group (G2) shows greater regularity, lower DF and spectral dispersion. These factors should be interpreted as a more stable cardiac response to V

Relación entre el espectro y la regularidad en la señal de fibrilación ventricular modificada por el ejercicio físico

El presente trabajo estudia las modificaciones intrínsecas que el ejercicio físico produce en la respuesta cardíaca durante la FV. Se han calculado dos parámetros relacionados con el espectro de la señal (FD: frecuencia dominante, y EN: energía normalizada), y otro relacionado con la regularidad de las OAL (IR: índice de regularidad), Se ha realizado un análisis de correlación entre los tres parámetros para valorar su grado de complementariedad. Se consideraron dos grupos de conejos: control (G1: sin entrenamiento, N=10) y entrenados (G2, N=9). Se utilizó un electrodo matricial de 240 canales localizado en ventrículo izquierdo de corazón aislado de conejo perfundido mediante un sistema de Langendorff. La FV se indujo por estimulación a frecuencias crecientes. Los resultados muestran que el grupo entrenado presenta una mayor regularidad de la señal (IR: G1: 0,757+-0,091; G2: 0,845+-0,084; p<0.001), así como menor FD (G1: 18.23±2.96Hz; G2: 14.13+-1.73Hz; p<0.001) y dispersión espectral (EN: G1: 0,138+-0.105; G2: 0,293+-0,176; p<0.001). El análisis de las relaciones entre parámetros muestra correlaciones significativas entre los parámetros para todos los casos excepto para IR y FD en G2, por lo que estos parámetros proporcionan información complementaria, ya que analizan aspectos diferentes de la señal como la morfología de las ondas de activación y su frecuencia. La existencia de correlación entre ambas para G1 puede ser debida a otras causas, tales como las modificaciones en ambos factores inducidas por la presencia de reentradas o colisiones entre frentes de activación.. Como conclusión, los resultados obtenidos sugieren que el entrenamiento físico produce una respuesta cardíaca más estable ante FV, debida a modificaciones intrínsecas en las características electrofisiológicas cardíacas

Analysis of the influence of parasympathetic postganglionic neurons on cardiac response in ventricular fibrillation

Physical training modifies the sympathetic-vagal balance of autonomic nervous system. Previous studies have shown that such training also produces intrinsic modifications of cardiac electrophysiological properties in isolated heart during Ventricular Fibrillation (VF). Ten NZW trained rabbits were studied to test if the modifications are related to the activity of postganglionic parasympathetic neurons. Two records per subject were acquired during VF: before (G1) and after (G2) the infusion of atropine to inhibit the activity of neurons. Mapping records were obtained using a 240-channel electrode array located in the left ventricle of isolated heart (perfused by Langendorff system). VF was induced by stimulation at increasing frequencies. To analyze the time course of fibrillation, the records were processed in 4-second consecutive segments. For each channel and segment, the following parameters were computed: 1) Dominant Frequency (DF), obtained by the Welch periodogram b) Normalized Energy (NE) in a frequency band centered at the DF; c) Regularity Index (RI), which analyzes the similarity of local activation waves in every segment and channel; d) Coefficients of Variance of DF (CVDF), NE (CVNE) and RI (CVRI). For each segment, we obtained the average value of each of the parameters analyzed for all electrodes. The results are: a) DF (G1: 13.671 ± 0.509 Hz, G2: 14.783 ± 0.455 Hz), b) NE (G1: 0.398 ± 0.014; G2: 0.380 ± 0.013); c) RI (G1: 0.855 ± 0.017; G2: 0.865 ± 0.015), d) CVDF (G1: 0.109 ± 0.009; G2: 0.098 ± 0.008), e) CVNE (G1: 0.398 ± 0.014; G2: 0.380 ± 0.013 ) f) CVRI (G1: 0.084 ± 0.009; G2: 0.078 ± 0.008). None of these parameters showed significant differences between groups. Thus, the parasympathetic postganglionic neurons seem to have no effect on the cardiac response in VF due to physical training

Development and validation of the Gender-Equity Model for Liver Allocation (GEMA) to prioritise candidates for liver transplantation: a cohort study

BACKGROUND: The Model for End-stage Liver Disease (MELD) and its sodium-corrected variant (MELD-Na) have created gender disparities in accessing liver transplantation. We aimed to derive and validate the Gender-Equity Model for liver Allocation (GEMA) and its sodium-corrected variant (GEMA-Na) to amend such inequities. METHODS: In this cohort study, the GEMA models were derived by replacing creatinine with the Royal Free Hospital glomerular filtration rate (RFH-GFR) within the MELD and MELD-Na formulas, with re-fitting and re-weighting of each component. The new models were trained and internally validated in adults listed for liver transplantation in the UK (2010-20; UK Transplant Registry) using generalised additive multivariable Cox regression, and externally validated in an Australian cohort (1998-2020; Royal Prince Alfred Hospital [Australian National Liver Transplant Unit] and Austin Hospital [Victorian Liver Transplant Unit]). The study comprised 9320 patients: 5762 patients for model training, 1920 patients for internal validation, and 1638 patients for external validation. The primary outcome was mortality or delisting due to clinical deterioration within the first 90 days from listing. Discrimination was assessed by Harrell's concordance statistic. FINDINGS: 449 (5·8%) of 7682 patients in the UK cohort and 87 (5·3%) of 1638 patients in the Australian cohort died or were delisted because of clinical deterioration within 90 days. GEMA showed improved discrimination in predicting mortality or delisting due to clinical deterioration within the first 90 days after waiting list inclusion compared with MELD (Harrell's concordance statistic 0·752 [95% CI 0·700-0·804] vs 0·712 [0·656-0·769]; p=0·001 in the internal validation group and 0·761 [0·703-0·819] vs 0·739 [0·682-0·796]; p=0·036 in the external validation group), and GEMA-Na showed improved discrimination compared with MELD-Na (0·766 [0·715-0·818] vs 0·742 [0·686-0·797]; p=0·0058 in the internal validation group and 0·774 [0·720-0·827] vs 0·745 [0·690-0·800]; p=0·014 in the external validation group). The discrimination capacity of GEMA-Na was higher in women than in the overall population, both in the internal (0·802 [0·716-0·888]) and external validation cohorts (0·796 [0·698-0·895]). In the pooled validation cohorts, GEMA resulted in a score change of at least 2 points compared with MELD in 1878 (52·8%) of 3558 patients (25·0% upgraded and 27·8% downgraded). GEMA-Na resulted in a score change of at least 2 points compared with MELD-Na in 1836 (51·6%) of 3558 patients (32·3% upgraded and 19·3% downgraded). In the whole cohort, 3725 patients received a transplant within 90 days of being listed. Of these patients, 586 (15·7%) would have been differently prioritised by GEMA compared with MELD; 468 (12·6%) patients would have been differently prioritised by GEMA-Na compared with MELD-Na. One in 15 deaths could potentially be avoided by using GEMA instead of MELD and one in 21 deaths could potentially be avoided by using GEMA-Na instead of MELD-Na. INTERPRETATION: GEMA and GEMA-Na showed improved discrimination and a significant re-classification benefit compared with existing scores, with consistent results in an external validation cohort. Their implementation could save a clinically meaningful number of lives, particularly among women, and could amend current gender inequities in accessing liver transplantation. FUNDING: Junta de Andalucía and EDRF

The photosynthetic cytochrome c 550 from the diatom Phaeodactylum tricornutum

The photosynthetic cytochrome c550 from the marine diatom Phaeodactylum tricornutum has been purified and characterized. Cytochrome c550 is mostly obtained from the soluble cell extract in relatively large amounts. In addition, the protein appeared to be truncated in the last hydrophobic residues of the C-terminus, both in the soluble cytochrome c550 and in the protein extracted from the membrane fraction, as deduced by mass spectrometry analysis and the comparison with the gene sequence. Interestingly, it has been described that the C-terminus of cytochrome c550 forms a hydrophobic finger involved in the interaction with photosystem II in cyanobacteria. Cytochrome c550 was almost absent in solubilized photosystem II complex samples, in contrast with the PsbO and Psb31 extrinsic subunits, thus suggesting a lower affinity of cytochrome c550 for the photosystem II complex. Under iron-limiting conditions the amount of cytochrome c550 decreases up to about 45% as compared to iron-replete cells, pointing to an iron-regulated synthesis. Oxidized cytochrome c550 has been characterized using continuous wave EPR and pulse techniques, including HYSCORE, and the obtained results have been interpreted in terms of the electrostatic charge distribution in the surroundings of the heme centre.This work was supported by the Spanish Ministry of Economy and Competitiveness (BIO2012-35271, BIO2015-64169-P, MAT2011-23861 and CTQ2015-64486-R) the Andalusian Government (PAIDI BIO-022) and the Aragón Government (Grupo consolidado B-18). All these grants were partially financed by the EU FEDER ProgramPeer reviewe